[INFO] cloning repository https://github.com/aquamarine-z/backend_connector
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/aquamarine-z/backend_connector" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Faquamarine-z%2Fbackend_connector", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Faquamarine-z%2Fbackend_connector'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] f9dc25ac2470c12d4fbaac2e156b21a264fe9f2a
[INFO] checking aquamarine-z/backend_connector against try#18c1d185ac7a6a3bf399296b35e4b2736809a756 for pr-146972
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Faquamarine-z%2Fbackend_connector" "/workspace/builds/worker-6-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/aquamarine-z/backend_connector
[INFO] finished tweaking git repo https://github.com/aquamarine-z/backend_connector
[INFO] tweaked toml for git repo https://github.com/aquamarine-z/backend_connector written to /workspace/builds/worker-6-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/aquamarine-z/backend_connector on toolchain 18c1d185ac7a6a3bf399296b35e4b2736809a756
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+18c1d185ac7a6a3bf399296b35e4b2736809a756" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/aquamarine-z/backend_connector already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+18c1d185ac7a6a3bf399296b35e4b2736809a756" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[ERROR] error running command: no output for 300 seconds
[INFO] checking aquamarine-z/backend_connector against try#18c1d185ac7a6a3bf399296b35e4b2736809a756 for pr-146972
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Faquamarine-z%2Fbackend_connector" "/workspace/builds/worker-6-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/aquamarine-z/backend_connector
[INFO] finished tweaking git repo https://github.com/aquamarine-z/backend_connector
[INFO] tweaked toml for git repo https://github.com/aquamarine-z/backend_connector written to /workspace/builds/worker-6-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/aquamarine-z/backend_connector on toolchain 18c1d185ac7a6a3bf399296b35e4b2736809a756
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+18c1d185ac7a6a3bf399296b35e4b2736809a756" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/aquamarine-z/backend_connector already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+18c1d185ac7a6a3bf399296b35e4b2736809a756" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:94a0c148923f5b2b52a63ef0eeb1882ad339ab61bce784c8077cbe41c61feb6c" "/opt/rustwide/cargo-home/bin/cargo" "+18c1d185ac7a6a3bf399296b35e4b2736809a756" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 871a6e2d82979dbe1adfd7f93460f1c6192f0d8821293aa7b620940dfc95dfff
[INFO] running `Command { std: "docker" "start" "-a" "871a6e2d82979dbe1adfd7f93460f1c6192f0d8821293aa7b620940dfc95dfff", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "871a6e2d82979dbe1adfd7f93460f1c6192f0d8821293aa7b620940dfc95dfff", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "871a6e2d82979dbe1adfd7f93460f1c6192f0d8821293aa7b620940dfc95dfff", kill_on_drop: false }`
[INFO] [stdout] 871a6e2d82979dbe1adfd7f93460f1c6192f0d8821293aa7b620940dfc95dfff
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "RUSTDOCFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:94a0c148923f5b2b52a63ef0eeb1882ad339ab61bce784c8077cbe41c61feb6c" "/opt/rustwide/cargo-home/bin/cargo" "+18c1d185ac7a6a3bf399296b35e4b2736809a756" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 9a11014946a62edddb595598a80d1d78ead680ddf97c7bd03c088c7bf4418c83
[INFO] running `Command { std: "docker" "start" "-a" "9a11014946a62edddb595598a80d1d78ead680ddf97c7bd03c088c7bf4418c83", kill_on_drop: false }`
[INFO] [stderr]     Checking backend_connector v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0106]: missing lifetime specifier
[INFO] [stdout]   --> src/backend_pool.rs:32:55
[INFO] [stdout]    |
[INFO] [stdout] 32 |     pub fn get_backend_at(self, index: i32) -> Option<&dyn Backend> {
[INFO] [stdout]    |                                                       ^ expected named lifetime parameter
[INFO] [stdout]    |
[INFO] [stdout]    = help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
[INFO] [stdout] help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`
[INFO] [stdout]    |
[INFO] [stdout] 32 |     pub fn get_backend_at(self, index: i32) -> Option<&'static dyn Backend> {
[INFO] [stdout]    |                                                        +++++++
[INFO] [stdout] help: instead, you are more likely to want to change one of the arguments to be borrowed...
[INFO] [stdout]    |
[INFO] [stdout] 32 |     pub fn get_backend_at(&self, index: &i32) -> Option<&dyn Backend> {
[INFO] [stdout]    |                           +             +
[INFO] [stdout] help: ...or alternatively, you might want to return an owned value
[INFO] [stdout]    |
[INFO] [stdout] 32 -     pub fn get_backend_at(self, index: i32) -> Option<&dyn Backend> {
[INFO] [stdout] 32 +     pub fn get_backend_at(self, index: i32) -> Option<dyn Backend> {
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0106]: missing lifetime specifier
[INFO] [stdout]   --> src/backend_pool.rs:32:55
[INFO] [stdout]    |
[INFO] [stdout] 32 |     pub fn get_backend_at(self, index: i32) -> Option<&dyn Backend> {
[INFO] [stdout]    |                                                       ^ expected named lifetime parameter
[INFO] [stdout]    |
[INFO] [stdout]    = help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
[INFO] [stdout] help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`
[INFO] [stdout]    |
[INFO] [stdout] 32 |     pub fn get_backend_at(self, index: i32) -> Option<&'static dyn Backend> {
[INFO] [stdout]    |                                                        +++++++
[INFO] [stdout] help: instead, you are more likely to want to change one of the arguments to be borrowed...
[INFO] [stdout]    |
[INFO] [stdout] 32 |     pub fn get_backend_at(&self, index: &i32) -> Option<&dyn Backend> {
[INFO] [stdout]    |                           +             +
[INFO] [stdout] help: ...or alternatively, you might want to return an owned value
[INFO] [stdout]    |
[INFO] [stdout] 32 -     pub fn get_backend_at(self, index: i32) -> Option<&dyn Backend> {
[INFO] [stdout] 32 +     pub fn get_backend_at(self, index: i32) -> Option<dyn Backend> {
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `crate::backend::Backend`
[INFO] [stdout]  --> src/backend_starter.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use crate::backend::Backend;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::time::Duration`
[INFO] [stdout]   --> src/backend_pool.rs:58:9
[INFO] [stdout]    |
[INFO] [stdout] 58 |     use std::time::Duration;
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `crate::add`
[INFO] [stdout]   --> src/backend_pool.rs:59:9
[INFO] [stdout]    |
[INFO] [stdout] 59 |     use crate::add;
[INFO] [stdout]    |         ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `Backend`
[INFO] [stdout]   --> src/backend_pool.rs:60:26
[INFO] [stdout]    |
[INFO] [stdout] 60 |     use crate::backend::{Backend, PythonBackend};
[INFO] [stdout]    |                          ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `crate::backend_pool::BackendPool`
[INFO] [stdout]   --> src/backend_pool.rs:61:9
[INFO] [stdout]    |
[INFO] [stdout] 61 |     use crate::backend_pool::BackendPool;
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `crate::add`
[INFO] [stdout]   --> src/port.rs:19:9
[INFO] [stdout]    |
[INFO] [stdout] 19 |     use crate::add;
[INFO] [stdout]    |         ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `crate::backend::Backend`
[INFO] [stdout]  --> src/backend_starter.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use crate::backend::Backend;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0053]: method `start_backend` has an incompatible type for trait
[INFO] [stdout]   --> src/backend_starter.rs:30:22
[INFO] [stdout]    |
[INFO] [stdout] 30 |     fn start_backend(self,port:u32){
[INFO] [stdout]    |                      ^^^^ expected `&PythonBackendStarter`, found `PythonBackendStarter`
[INFO] [stdout]    |
[INFO] [stdout] note: type in trait
[INFO] [stdout]   --> src/backend_starter.rs:5:22
[INFO] [stdout]    |
[INFO] [stdout]  5 |     fn start_backend(&self,port:u32);
[INFO] [stdout]    |                      ^^^^^
[INFO] [stdout]    = note: expected signature `fn(&PythonBackendStarter, _)`
[INFO] [stdout]               found signature `fn(PythonBackendStarter, _)`
[INFO] [stdout] help: change the self-receiver type to match the trait
[INFO] [stdout]    |
[INFO] [stdout] 30 |     fn start_backend(&self,port:u32){
[INFO] [stdout]    |                      +
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0053]: method `start_backend` has an incompatible type for trait
[INFO] [stdout]   --> src/backend_starter.rs:30:22
[INFO] [stdout]    |
[INFO] [stdout] 30 |     fn start_backend(self,port:u32){
[INFO] [stdout]    |                      ^^^^ expected `&PythonBackendStarter`, found `PythonBackendStarter`
[INFO] [stdout]    |
[INFO] [stdout] note: type in trait
[INFO] [stdout]   --> src/backend_starter.rs:5:22
[INFO] [stdout]    |
[INFO] [stdout]  5 |     fn start_backend(&self,port:u32);
[INFO] [stdout]    |                      ^^^^^
[INFO] [stdout]    = note: expected signature `fn(&PythonBackendStarter, _)`
[INFO] [stdout]               found signature `fn(PythonBackendStarter, _)`
[INFO] [stdout] help: change the self-receiver type to match the trait
[INFO] [stdout]    |
[INFO] [stdout] 30 |     fn start_backend(&self,port:u32){
[INFO] [stdout]    |                      +
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0599]: the method `clone` exists for struct `Box<(dyn BackendStarter + 'static)>`, but its trait bounds were not satisfied
[INFO] [stdout]   --> src/backend.rs:28:29
[INFO] [stdout]    |
[INFO] [stdout] 28 |         return self.starter.clone();
[INFO] [stdout]    |                             ^^^^^ method cannot be called on `Box<(dyn BackendStarter + 'static)>` due to unsatisfied trait bounds
[INFO] [stdout]    |
[INFO] [stdout]   ::: src/backend_starter.rs:4:1
[INFO] [stdout]    |
[INFO] [stdout]  4 | pub trait BackendStarter{
[INFO] [stdout]    | ------------------------ doesn't satisfy `dyn BackendStarter: Clone` or `dyn BackendStarter: Sized`
[INFO] [stdout]    |
[INFO] [stdout]    = note: the following trait bounds were not satisfied:
[INFO] [stdout]            `dyn BackendStarter: Sized`
[INFO] [stdout]            which is required by `Box<dyn BackendStarter>: Clone`
[INFO] [stdout]            `dyn BackendStarter: Clone`
[INFO] [stdout]            which is required by `Box<dyn BackendStarter>: Clone`
[INFO] [stdout]    = help: items from traits can only be used if the trait is implemented and in scope
[INFO] [stdout]    = note: the following trait defines an item `clone`, perhaps you need to implement it:
[INFO] [stdout]            candidate #1: `Clone`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0599]: the method `clone` exists for struct `Box<(dyn BackendStarter + 'static)>`, but its trait bounds were not satisfied
[INFO] [stdout]   --> src/backend.rs:28:29
[INFO] [stdout]    |
[INFO] [stdout] 28 |         return self.starter.clone();
[INFO] [stdout]    |                             ^^^^^ method cannot be called on `Box<(dyn BackendStarter + 'static)>` due to unsatisfied trait bounds
[INFO] [stdout]    |
[INFO] [stdout]   ::: src/backend_starter.rs:4:1
[INFO] [stdout]    |
[INFO] [stdout]  4 | pub trait BackendStarter{
[INFO] [stdout]    | ------------------------ doesn't satisfy `dyn BackendStarter: Clone` or `dyn BackendStarter: Sized`
[INFO] [stdout]    |
[INFO] [stdout]    = note: the following trait bounds were not satisfied:
[INFO] [stdout]            `dyn BackendStarter: Sized`
[INFO] [stdout]            which is required by `Box<dyn BackendStarter>: Clone`
[INFO] [stdout]            `dyn BackendStarter: Clone`
[INFO] [stdout]            which is required by `Box<dyn BackendStarter>: Clone`
[INFO] [stdout]    = help: items from traits can only be used if the trait is implemented and in scope
[INFO] [stdout]    = note: the following trait defines an item `clone`, perhaps you need to implement it:
[INFO] [stdout]            candidate #1: `Clone`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0599]: the method `clone` exists for struct `Box<(dyn BackendStarter + 'static)>`, but its trait bounds were not satisfied
[INFO] [stdout]   --> src/backend.rs:54:29
[INFO] [stdout]    |
[INFO] [stdout] 54 |         return self.starter.clone();
[INFO] [stdout]    |                             ^^^^^ method cannot be called on `Box<(dyn BackendStarter + 'static)>` due to unsatisfied trait bounds
[INFO] [stdout]    |
[INFO] [stdout]   ::: src/backend_starter.rs:4:1
[INFO] [stdout]    |
[INFO] [stdout]  4 | pub trait BackendStarter{
[INFO] [stdout]    | ------------------------ doesn't satisfy `dyn BackendStarter: Clone` or `dyn BackendStarter: Sized`
[INFO] [stdout]    |
[INFO] [stdout]    = note: the following trait bounds were not satisfied:
[INFO] [stdout]            `dyn BackendStarter: Sized`
[INFO] [stdout]            which is required by `Box<dyn BackendStarter>: Clone`
[INFO] [stdout]            `dyn BackendStarter: Clone`
[INFO] [stdout]            which is required by `Box<dyn BackendStarter>: Clone`
[INFO] [stdout]    = help: items from traits can only be used if the trait is implemented and in scope
[INFO] [stdout]    = note: the following trait defines an item `clone`, perhaps you need to implement it:
[INFO] [stdout]            candidate #1: `Clone`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0599]: the method `clone` exists for struct `Box<(dyn BackendStarter + 'static)>`, but its trait bounds were not satisfied
[INFO] [stdout]   --> src/backend.rs:54:29
[INFO] [stdout]    |
[INFO] [stdout] 54 |         return self.starter.clone();
[INFO] [stdout]    |                             ^^^^^ method cannot be called on `Box<(dyn BackendStarter + 'static)>` due to unsatisfied trait bounds
[INFO] [stdout]    |
[INFO] [stdout]   ::: src/backend_starter.rs:4:1
[INFO] [stdout]    |
[INFO] [stdout]  4 | pub trait BackendStarter{
[INFO] [stdout]    | ------------------------ doesn't satisfy `dyn BackendStarter: Clone` or `dyn BackendStarter: Sized`
[INFO] [stdout]    |
[INFO] [stdout]    = note: the following trait bounds were not satisfied:
[INFO] [stdout]            `dyn BackendStarter: Sized`
[INFO] [stdout]            which is required by `Box<dyn BackendStarter>: Clone`
[INFO] [stdout]            `dyn BackendStarter: Clone`
[INFO] [stdout]            which is required by `Box<dyn BackendStarter>: Clone`
[INFO] [stdout]    = help: items from traits can only be used if the trait is implemented and in scope
[INFO] [stdout]    = note: the following trait defines an item `clone`, perhaps you need to implement it:
[INFO] [stdout]            candidate #1: `Clone`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0599]: no method named `get_start_command` found for reference `&Box<dyn Backend>` in the current scope
[INFO] [stdout]   --> src/backend_pool.rs:49:25
[INFO] [stdout]    |
[INFO] [stdout] 49 |                 backend.get_start_command(1);
[INFO] [stdout]    |                         ^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout] help: there is a method `get_starter` with a similar name, but with different arguments
[INFO] [stdout]   --> src/backend.rs:18:5
[INFO] [stdout]    |
[INFO] [stdout] 18 |     fn get_starter(&self)->Box<dyn BackendStarter>;
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0599]: no method named `get_start_command` found for reference `&Box<dyn Backend>` in the current scope
[INFO] [stdout]   --> src/backend_pool.rs:49:25
[INFO] [stdout]    |
[INFO] [stdout] 49 |                 backend.get_start_command(1);
[INFO] [stdout]    |                         ^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout] help: there is a method `get_starter` with a similar name, but with different arguments
[INFO] [stdout]   --> src/backend.rs:18:5
[INFO] [stdout]    |
[INFO] [stdout] 18 |     fn get_starter(&self)->Box<dyn BackendStarter>;
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `e`
[INFO] [stdout]   --> src/port.rs:14:13
[INFO] [stdout]    |
[INFO] [stdout] 14 |         Err(ref e) => true, // 其他错误直接返回
[INFO] [stdout]    |             ^^^^^ help: if this is intentional, prefix it with an underscore: `_e`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/backend_starter.rs:15:13
[INFO] [stdout]    |
[INFO] [stdout] 15 |         let mut cmd = std::process::Command::new("cmd");
[INFO] [stdout]    |             ----^^^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `cmd`
[INFO] [stdout]   --> src/backend_starter.rs:15:13
[INFO] [stdout]    |
[INFO] [stdout] 15 |         let mut cmd = std::process::Command::new("cmd");
[INFO] [stdout]    |             ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_cmd`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/backend_pool.rs:65:13
[INFO] [stdout]    |
[INFO] [stdout] 65 |         let mut backend=PythonBackend::new(
[INFO] [stdout]    |             ----^^^^^^^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `e`
[INFO] [stdout]   --> src/port.rs:14:13
[INFO] [stdout]    |
[INFO] [stdout] 14 |         Err(ref e) => true, // 其他错误直接返回
[INFO] [stdout]    |             ^^^^^ help: if this is intentional, prefix it with an underscore: `_e`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/backend_starter.rs:15:13
[INFO] [stdout]    |
[INFO] [stdout] 15 |         let mut cmd = std::process::Command::new("cmd");
[INFO] [stdout]    |             ----^^^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `cmd`
[INFO] [stdout]   --> src/backend_starter.rs:15:13
[INFO] [stdout]    |
[INFO] [stdout] 15 |         let mut cmd = std::process::Command::new("cmd");
[INFO] [stdout]    |             ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_cmd`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0053, E0106, E0599.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0053`.
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0053, E0106, E0599.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0053`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `backend_connector` (lib) due to 5 previous errors; 4 warnings emitted
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: could not compile `backend_connector` (lib test) due to 5 previous errors; 10 warnings emitted
[INFO] running `Command { std: "docker" "inspect" "9a11014946a62edddb595598a80d1d78ead680ddf97c7bd03c088c7bf4418c83", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9a11014946a62edddb595598a80d1d78ead680ddf97c7bd03c088c7bf4418c83", kill_on_drop: false }`
[INFO] [stdout] 9a11014946a62edddb595598a80d1d78ead680ddf97c7bd03c088c7bf4418c83
